@mcw, this is pushing the boundaries of "simple editor" use cases imho. But one reason this came up for me is that in doing cleanup work, it's sometimes handy to know the specific node. For example, single node ways within other ways (ie see http://tools.geofabrik.de/osmi/?view=geometry) Maybe others have a more general use?

@mcw: If you want to look up an element's history with a tool like osm-deep-history you need the id. If you want to hide how OSM really works as much as possible then not showing is right. I also think that most beginner mappers will not need a id. But could it be that exactly that hiding is inducing low performance and being unsure? Oh, well - by the way, wrong place to discuss here. ;-)

@mcw Why show the ID? Well, it's convenient to make sure I'm editing the right object. It's also essential when working with relations: there's really no way to make sure I'm adding to the right relation without seeing an ID number. It wouldn't complicate the UI—Potlatch has done it very simply for years—and it's necessary for an OSM editor that isn't just a toy. Also, it's ironic that the iD editor doesn't show IDs! :)

Well, when you select an object, a panel opens on the right (the 'feature editor'), and towards the bottom (you may have to scroll) there's a link to 'View on openstreetmap.org'. Just hovering over the link will probably display the URL containing the object's ID (most browsers do that, I think).

@neuhausr: also works for nodes (if they don't have tags you need to click on "other" (last entry) in the right panel first - other selections add tags). Remember the target audience of iD (read e.g. there) - who cares for object ids?

I often find myself wanting to find out about a history of something I'm trying to edit in ID (to understand if needs to be changed when deciding which source is more uptodate for instance; when it gets unclear).

My solution was just to right click the browser on the openstreetmap name at the top left to open OSM at the same place in a new tag or window then just use the data-view or qurey feeature to study all the parts of concern before move back to the unstopped id session to carry on with the edit. I do the same to get access to the wiki manual pages when don't remeber the tags enough to bring the id mini help on tags (and its helpful link)